Go Fix It: Implement technology within current infrastructure systems to bring about increased energy efficiency and sustainability
Methane Capture, Flywheel Energy Storage and Waste Heat Recovery
INTRODUCTION
- Our current system of energy supply and use is one of the world’s largest sustainability problems
- In terms of fixing many of these problems in general renewable power generation attracts more entrepreneurs and investors, but often the economics of efficiency within current infrastructure is much stronger and the technology can be implemented much quicker and easier(7)
- “by and large the world ignores the biggest most cost effective most profitable thing to do which is to recycle the energy that we’re wasting” says Thomas Caster, chairman of an Illinois based company Recycled Energy Development talking about energy conservation (6)
- These potential short term solutions can bring about reduced impact on the environment and increased sustainability, there are lots of ways we can reduce
- These ideas can be implemented alongside the development of renewable power generation methods on our way to achieving a completely sustainable energy supply
- Go fix it by working with our system to make it more sustainable instead of completely reworking everything and achieving a mindset among all industries of a closed loop cycle to as much of a degree as possible with respect to energy
METHANE CAPTURE
Landfills and Methane Production:
- 69.5% of landfill waste on average is biomass (paper/paperboard, wood, yard trimmings, food, cotton, wool, leather etc…..) which contributes to methane production (4)
- When this waste breaks down it produces gas which is between 45% and 60% methane (1)
- Methane is a greenhouse gas with 25x more heat trapping capabilities than CO2 (1)
- The remaining percentage of this gas is largely CO2 but this raw gas can be separated somewhat easily using liquid-vapor separating processes to produce nearly pure methane closely resembling that used typically for fuel (1)
- Vertical wells and horizontal collectors may be put into place to direct the flow of gas within the landfill, this is “passive gas collection” and may be performed during initial construction or after the landfill is closed (1)
- Important factors affecting the quality of the landfill gas that will be produced over the lifetime of the landfill include: waste composition (more organic waste more gas produced as bacteria break it down), age of refuse (peak gas production occurs 5 to 7 years after waste is buried), presence of oxygen (methane production requires anaerobic process), moisture content (more moisture increases output), temperature (greater temperatures increases bacterial activity)(1)
Current Landfill Situation:
- Over 3,000 active landfills exist in the U.S. and 10,000 inactive ones (1)
- Methane is 17% of total global greenhouse gas emissions (2)
- Landfills account for 23% of total methane emissions in U.S. in 2007(1)
- Roughly 500 landfills in the US practice methane capture; 70% utilize it for energy and 30% simply flare it off turning it into CO2 which has less global warming potential(1)
- This means there are approximately 327 “landfill gas-to-energy” plants in the US; 71% produce electricity directly through on site turbines, 21% sell gas to users for home heating and 4% pressurize it and put it back into the natural gas pipelines(4)
- 1190 Mw of electricity was generated in 2008 from these plants, this minimal amount of methane capture displaced over 2,100,000 pounds of coal and captured about 60% to 90% of the methane created, preventing it from entering the atmosphere (1)
- There are about 1000 of these plants around the world which collect about 2.6 million tons of methane annually (4)
- U.S. Congress has a “Landfill Gas Rule” that says any landfill with over a 2.5 million metric ton design capacity that has accepted waste since 1987 must capture and burn its gas (2)
- Very few projects exist in small landfills in which the gas may serve whole communities’ needs and which represent a significant number of the total number of landfills(2)
Energy and Climate Change Implications for Methane Capture:
- Roughly 24% of U.S. energy consumed in 2008 was fueled by natural gas which is primarily methane, therefore the infrastructure to use this gas is already established (2)
- Methane has global warming potential 25 times that of CO2 and also has a short atmospheric lifetime of only 12 years so a reduction in emissions of this gas in particular has significant potential to bring about more near term climate change abatement (2)
- Journal article estimates at least 50nm3 of methane can be produced per ton of MSW (municipal solid waste) as a conservative average estimate, with an estimated global land filling rate of 1.5 billion tons annually this corresponds to a methane generation of 75 billion nm3, less than 10% of this potential is captured and utilized at this time(4)
- In more readily understood units this corresponds to about 50 million tons of methane that could reasonably be produced on a global scale and only about 5 million tons is currently captured and utilized (4)
- This theoretical study does estimate that up to four times as much could be achieved and some more modern landfills have seen up to twice as much methane collection per ton already (4)
- Advanced methane capture promises 98% capture rate of methane within landfills preventing nearly all greenhouse gas emissions from this source (5)
- An estimated three million homes in the U.S. alone could be powered by methane if all landfills adopted this modern technology (5)
- For more information see this comprehension study into the potential of methane capture and landfills including specific waste, emissions and energy data for a variety of U.S. and global landfills:
- “waste-heat recovery boilers” use the heat from industrial smoke stacks to produce steam to spin a turbine and generate electricity (6)
- Reuse heat that would otherwise be lost to the skies through these smokestacks (7)
- Through this waste heat recovery with currently available technology U.S. could generate the equivalent of 400 coal-fired power plants (7)
- With some new developing technology it is estimated this area could provide very practically up to 20% of the US power needs and products would be about the same cost as conventional turbines (8)
Older Technology:
- The oldest systems for waste heat recovery involves putting coils around smokestacks or equipment to heat water which either is turned into pressurized steam for electricity or is pumped back to the facility for preheating in industrial processes reducing energy inputs (8)
- Steam must be raised to 650°C and below 450°C it doesn’t operate efficiently so only smokestacks with very high temperatures can be used in this system (7)
- 500,000 smokestacks exist in the United States and roughly 47,500 produce waste heat of adequate temperature for this system (6)
- If this was implemented onto all of these it could produce upwards of 50,000 MW of power (6)
Modern Technology:
- Uses propane vapor rather than steam to turn a turbine and drive an electric generator (8)
- Propane’s lower boiling point allows it to be vaporized at temperatures between 150°C and 450°C which includes a far greater percentage of industrial sources (8)
- This is known as an Organic Rankine Cycle and is also being implemented within geothermal power plants (8)
- Oven or furnace exhausts, cement kilns, flue gas discharges, process water or other fluids in food processing, plastics and metal industries could all utilize this technology (8)
- If worldwide compliance and use of this technology was implemented it would become a very significant source of cheap energy that would displace a significant percentage of fossil fuel use; meanwhile no new power plants would have to be developed as this power would be generated on site at existing industrial facilities
Future Application and Emerging technology:
- Double generator system developed by WOWEnergy utilizes almost all waste heat available, a second turbine is driven by the waste heat from the first with leftover flue gases to emerge as low as 55°C (8)
- At 55°C many pollutants that enter the atmosphere today such as mercury oxide and cadmium oxide would instead condense inside the stack where they could be easily removed (8)
- Idea has not been properly tested though(8)
- For more information see the following WOWEnergy Corporation brochure:
- Thermoelectric modules are also under development which create electricity directly from heat removing the need for expensive turbines (7)
- Use lost heat from your furnace to power your home or capture the waste heat from your car exhaust? Neither of these are products but these are some of the potential application for these modules which are under development by researchers at MIT and Boston College(7)
- See the following link for an article discussing the potential for these thermoelectric modules and waste heat in general:
- Involves feeding energy into a rotational mass known as a flywheel where it is stored as kinetic energy which can be drawn upon when needed (9)
- Mathematics have been around for this since early 1990s but modern carbon fiber materials, vacuum chambers and floating bearing technologies have greatly improved efficiency and storage capabilities
- Able to operate at high storage efficiencies of around 93%, the University of Texas at Austin has developed a system that spins at 48,000 rpm (roughly mach 2 surface speed) during more than 90,000 charge-discharge cycles without loss of functionality (9)
- Eliminates thousands of pounds of lead and chemicals that would be in batteries(11)
- Meanwhile they have many other technical advantages over batteries including: unaffected by cycling, broad temperature range capabilities and similar or less float energy (11)
Applications:
- Flywheel Energy Systems in vehicles: average power needed to propel the vehicle is applied by the engine allowing the engine to operate at constant optimum efficiency and speed reducing fuel consumption, air and noise pollution and extending the engine life (9)
- Short bursts of power for acceleration and traveling up hills are taken from the rotating flywheel which is then slowly replaced by the engine; also regenerative braking speeds up the flywheel while the car slows down capturing this energy so that it can then be used again for acceleration(9)
- Something unlike hydrogen or full electric vehicles which could be easily implemented into our current gasoline industry infrastructure, doesn’t require new or modified refueling stations like hydrogen power solutions or ethanol based solutions
- Although it would still most likely require new vehicles to be purchased it would in general be implemented within current engine technology making current engines more efficient
- This regenerative braking idea can be used in many other applications and a variety of lifting-lowering or acceleration-deceleration cycles including within elevators, cranes in shipyards and rail yards and in trains (11)
- Most people look to this technology for potential applications within wind and solar power generation due to the intermittent nature of these alternative energies outputs (9)
- This same idea could be used to smooth out changes in demand within the fossil fuel industries themselves. Flywheels can react quickly to changes in demand and are much more efficient than bringing generators up and down (10)
- if generators could run at constant rates pollution effects and wasted energy could be reduced (10)
- For more information on flywheel energy products see the following corporations’ websites:
- More technical information about flywheels and information about various applications of flywheel energy can be found in the following Journal Article:
- Problems with implementing much of this technology include high costs to industry and safety issues, but if cost can be lowered then these could play a significant role in securing global energy sustainability(9)
- Any programs supporting this technology that exist within government at this time are purely voluntary for industry (2)
- Some common solutions to bringing about implementation of this type of technology include market based emission control programs, carbon offsets and emission performance standards (2)
- This project focuses mostly on the idea that this technology is out there and that there are a variety of ways we can increase the sustainability of our energy supply without developing completely new ways to produce energy like solar, wind and nuclear
- For details on how these industries could be strengthened see the congressional document talking about methane capture that was prepared for the committee on climate change: http://fpc.state.gov/documents/organization/130799.pdf
- These ideas may still cost significant amount of money but more on the order of millions and not billions like some larger scale alternatives to energy problems that would require vast infrastructure changes
- Even if we do start to implement new infrastructure changes it will not be instantaneous and undoubtedly many current systems will coexist with this new infrastructure
- Some of these ideas can help bring about a sense of community as a starting point to areas living and operating more locally, a communities energy could be supplied directly by a local industrial plant or landfill increasing people’s awareness of the source of their energy and providing a sense of dependence on things around you
- Jevens Paradox must be addressed along with this project as it directly contradicts the idea that efficiency will bring about increased sustainability. These ideas that are presented must be coupled with reduced use initiatives as well to be truly effective
Methane Capture, Flywheel Energy Storage and Waste Heat Recovery
INTRODUCTION
- Our current system of energy supply and use is one of the world’s largest sustainability problems
- In terms of fixing many of these problems in general renewable power generation attracts more entrepreneurs and investors, but often the economics of efficiency within current infrastructure is much stronger and the technology can be implemented much quicker and easier(7)
- “by and large the world ignores the biggest most cost effective most profitable thing to do which is to recycle the energy that we’re wasting” says Thomas Caster, chairman of an Illinois based company Recycled Energy Development talking about energy conservation (6)
- These potential short term solutions can bring about reduced impact on the environment and increased sustainability, there are lots of ways we can reduce
- These ideas can be implemented alongside the development of renewable power generation methods on our way to achieving a completely sustainable energy supply
- Go fix it by working with our system to make it more sustainable instead of completely reworking everything and achieving a mindset among all industries of a closed loop cycle to as much of a degree as possible with respect to energy
METHANE CAPTURE
Landfills and Methane Production:
- 69.5% of landfill waste on average is biomass (paper/paperboard, wood, yard trimmings, food, cotton, wool, leather etc…..) which contributes to methane production (4)
- When this waste breaks down it produces gas which is between 45% and 60% methane (1)
- Methane is a greenhouse gas with 25x more heat trapping capabilities than CO2 (1)
- The remaining percentage of this gas is largely CO2 but this raw gas can be separated somewhat easily using liquid-vapor separating processes to produce nearly pure methane closely resembling that used typically for fuel (1)
- Vertical wells and horizontal collectors may be put into place to direct the flow of gas within the landfill, this is “passive gas collection” and may be performed during initial construction or after the landfill is closed (1)
- Important factors affecting the quality of the landfill gas that will be produced over the lifetime of the landfill include: waste composition (more organic waste more gas produced as bacteria break it down), age of refuse (peak gas production occurs 5 to 7 years after waste is buried), presence of oxygen (methane production requires anaerobic process), moisture content (more moisture increases output), temperature (greater temperatures increases bacterial activity)(1)
Current Landfill Situation:
- Over 3,000 active landfills exist in the U.S. and 10,000 inactive ones (1)
- Methane is 17% of total global greenhouse gas emissions (2)
- Landfills account for 23% of total methane emissions in U.S. in 2007(1)
- Roughly 500 landfills in the US practice methane capture; 70% utilize it for energy and 30% simply flare it off turning it into CO2 which has less global warming potential(1)
- This means there are approximately 327 “landfill gas-to-energy” plants in the US; 71% produce electricity directly through on site turbines, 21% sell gas to users for home heating and 4% pressurize it and put it back into the natural gas pipelines(4)
- 1190 Mw of electricity was generated in 2008 from these plants, this minimal amount of methane capture displaced over 2,100,000 pounds of coal and captured about 60% to 90% of the methane created, preventing it from entering the atmosphere (1)
- There are about 1000 of these plants around the world which collect about 2.6 million tons of methane annually (4)
- U.S. Congress has a “Landfill Gas Rule” that says any landfill with over a 2.5 million metric ton design capacity that has accepted waste since 1987 must capture and burn its gas (2)
- Very few projects exist in small landfills in which the gas may serve whole communities’ needs and which represent a significant number of the total number of landfills(2)
Energy and Climate Change Implications for Methane Capture:
- Roughly 24% of U.S. energy consumed in 2008 was fueled by natural gas which is primarily methane, therefore the infrastructure to use this gas is already established (2)
- Methane has global warming potential 25 times that of CO2 and also has a short atmospheric lifetime of only 12 years so a reduction in emissions of this gas in particular has significant potential to bring about more near term climate change abatement (2)
- Journal article estimates at least 50nm3 of methane can be produced per ton of MSW (municipal solid waste) as a conservative average estimate, with an estimated global land filling rate of 1.5 billion tons annually this corresponds to a methane generation of 75 billion nm3, less than 10% of this potential is captured and utilized at this time(4)
- In more readily understood units this corresponds to about 50 million tons of methane that could reasonably be produced on a global scale and only about 5 million tons is currently captured and utilized (4)
- This theoretical study does estimate that up to four times as much could be achieved and some more modern landfills have seen up to twice as much methane collection per ton already (4)
- Advanced methane capture promises 98% capture rate of methane within landfills preventing nearly all greenhouse gas emissions from this source (5)
- An estimated three million homes in the U.S. alone could be powered by methane if all landfills adopted this modern technology (5)
- For more information see this comprehension study into the potential of methane capture and landfills including specific waste, emissions and energy data for a variety of U.S. and global landfills:
http://www.sciencedirect.com.libproxy.rpi.edu/science?_ob=ArticleURL&_udi=B6V4S-4KJDWT2-1&_user=659639&_coverDate=06%2F30%2F2007&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000035878&_version=1&_urlVersion=0&_userid=659639&md5=17aaee5ae0b609025498f987f6f280bf
WASTE HEAT RECOVERY
Introduction and Implications of Use:
- “waste-heat recovery boilers” use the heat from industrial smoke stacks to produce steam to spin a turbine and generate electricity (6)
- Reuse heat that would otherwise be lost to the skies through these smokestacks (7)
- Through this waste heat recovery with currently available technology U.S. could generate the equivalent of 400 coal-fired power plants (7)
- With some new developing technology it is estimated this area could provide very practically up to 20% of the US power needs and products would be about the same cost as conventional turbines (8)
Older Technology:
- The oldest systems for waste heat recovery involves putting coils around smokestacks or equipment to heat water which either is turned into pressurized steam for electricity or is pumped back to the facility for preheating in industrial processes reducing energy inputs (8)
- Steam must be raised to 650°C and below 450°C it doesn’t operate efficiently so only smokestacks with very high temperatures can be used in this system (7)
- 500,000 smokestacks exist in the United States and roughly 47,500 produce waste heat of adequate temperature for this system (6)
- If this was implemented onto all of these it could produce upwards of 50,000 MW of power (6)
Modern Technology:
- Uses propane vapor rather than steam to turn a turbine and drive an electric generator (8)
- Propane’s lower boiling point allows it to be vaporized at temperatures between 150°C and 450°C which includes a far greater percentage of industrial sources (8)
- This is known as an Organic Rankine Cycle and is also being implemented within geothermal power plants (8)
- Oven or furnace exhausts, cement kilns, flue gas discharges, process water or other fluids in food processing, plastics and metal industries could all utilize this technology (8)
- If worldwide compliance and use of this technology was implemented it would become a very significant source of cheap energy that would displace a significant percentage of fossil fuel use; meanwhile no new power plants would have to be developed as this power would be generated on site at existing industrial facilities
Future Application and Emerging technology:
- Double generator system developed by WOWEnergy utilizes almost all waste heat available, a second turbine is driven by the waste heat from the first with leftover flue gases to emerge as low as 55°C (8)
- At 55°C many pollutants that enter the atmosphere today such as mercury oxide and cadmium oxide would instead condense inside the stack where they could be easily removed (8)
- Idea has not been properly tested though(8)
- For more information see the following WOWEnergy Corporation brochure:
http://www.wowenergies.com/WOW_Waste_to_energy_IF_P.pdf
- Thermoelectric modules are also under development which create electricity directly from heat removing the need for expensive turbines (7)
- Use lost heat from your furnace to power your home or capture the waste heat from your car exhaust? Neither of these are products but these are some of the potential application for these modules which are under development by researchers at MIT and Boston College(7)
- See the following link for an article discussing the potential for these thermoelectric modules and waste heat in general:
http://news.cnet.com/8301-11128_3-10019347-54.html
FLYWHEEL ENERGY STORAGE
The Technology:
- Involves feeding energy into a rotational mass known as a flywheel where it is stored as kinetic energy which can be drawn upon when needed (9)
- Mathematics have been around for this since early 1990s but modern carbon fiber materials, vacuum chambers and floating bearing technologies have greatly improved efficiency and storage capabilities
- Able to operate at high storage efficiencies of around 93%, the University of Texas at Austin has developed a system that spins at 48,000 rpm (roughly mach 2 surface speed) during more than 90,000 charge-discharge cycles without loss of functionality (9)
- Eliminates thousands of pounds of lead and chemicals that would be in batteries(11)
- Meanwhile they have many other technical advantages over batteries including: unaffected by cycling, broad temperature range capabilities and similar or less float energy (11)
Applications:
- Flywheel Energy Systems in vehicles: average power needed to propel the vehicle is applied by the engine allowing the engine to operate at constant optimum efficiency and speed reducing fuel consumption, air and noise pollution and extending the engine life (9)
- Short bursts of power for acceleration and traveling up hills are taken from the rotating flywheel which is then slowly replaced by the engine; also regenerative braking speeds up the flywheel while the car slows down capturing this energy so that it can then be used again for acceleration(9)
- Something unlike hydrogen or full electric vehicles which could be easily implemented into our current gasoline industry infrastructure, doesn’t require new or modified refueling stations like hydrogen power solutions or ethanol based solutions
- Although it would still most likely require new vehicles to be purchased it would in general be implemented within current engine technology making current engines more efficient
- This regenerative braking idea can be used in many other applications and a variety of lifting-lowering or acceleration-deceleration cycles including within elevators, cranes in shipyards and rail yards and in trains (11)
- Most people look to this technology for potential applications within wind and solar power generation due to the intermittent nature of these alternative energies outputs (9)
- This same idea could be used to smooth out changes in demand within the fossil fuel industries themselves. Flywheels can react quickly to changes in demand and are much more efficient than bringing generators up and down (10)
- if generators could run at constant rates pollution effects and wasted energy could be reduced (10)
- For more information on flywheel energy products see the following corporations’ websites:
http://www.vyconenergy.com/pq/pages_pq/pqapps.htm
http://www.pentadyne.com/site/flywheel-ups/technology.html
- More technical information about flywheels and information about various applications of flywheel energy can be found in the following Journal Article:
http://www.sciencedirect.com.libproxy.rpi.edu/science?_ob=ArticleURL&_udi=B6V2V-4MG6P8C-1&_user=659639&_coverDate=05%2F31%2F2007&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000035878&_version=1&_urlVersion=0&_userid=659639&md5=ee3faec3d82411f8c337ab0c3c130639
CONCLUSION
- Problems with implementing much of this technology include high costs to industry and safety issues, but if cost can be lowered then these could play a significant role in securing global energy sustainability(9)
- Any programs supporting this technology that exist within government at this time are purely voluntary for industry (2)
- Some common solutions to bringing about implementation of this type of technology include market based emission control programs, carbon offsets and emission performance standards (2)
- This project focuses mostly on the idea that this technology is out there and that there are a variety of ways we can increase the sustainability of our energy supply without developing completely new ways to produce energy like solar, wind and nuclear
- For details on how these industries could be strengthened see the congressional document talking about methane capture that was prepared for the committee on climate change:
http://fpc.state.gov/documents/organization/130799.pdf
- These ideas may still cost significant amount of money but more on the order of millions and not billions like some larger scale alternatives to energy problems that would require vast infrastructure changes
- Even if we do start to implement new infrastructure changes it will not be instantaneous and undoubtedly many current systems will coexist with this new infrastructure
- Some of these ideas can help bring about a sense of community as a starting point to areas living and operating more locally, a communities energy could be supplied directly by a local industrial plant or landfill increasing people’s awareness of the source of their energy and providing a sense of dependence on things around you
- Jevens Paradox must be addressed along with this project as it directly contradicts the idea that efficiency will bring about increased sustainability. These ideas that are presented must be coupled with reduced use initiatives as well to be truly effective
REFERENCES
1. Landfill Gas. (n.d.). Retrieved April 24, 2010, from Climatelab: http://climatelab.org/Landfill_Methane?action=edit
2. Bracmort, K., Ramseur, J. L., McCarthy, J. E., Folger, P., & Marples, D. J. (2009, September 17). Methane Capture: Options for Greenhouse Gas Emission Reduction. Retrieved April 24, 2010, from http://fpc.state.gov/documents/organization/130799.pdf
3. Mulholland, T. (2007, November 13). Methane capture technology offers double benefit for transport and environment. Retrieved April 24, 2010, from The New York Times: http://www.nytimes.com/2007/11/13/news/13iht-renmeth.1.8311233.html?_r=3
4. Themelis, N. J., & Ulloa, P. A. (2007). Methane generation in landfills. Renewable Energy , 1243-1257.
5. Burkart, K. (2009, February 21). Landfill methane could power 3 million homes. Retrieved April 24, 2010, from mothernaturenetwork: http://www.mnn.com/green-tech/research-innovations/blogs/landfill-methane-could-power-3-million-homes
6. Herro, A. (2007, November 19). Clean Energy's Best-Kept Secret: Waste Heat Recovery. Retrieved April 24, 2010, from Environmental News Network: http://www.enn.com/energy/article/25399
7. LaMonica, M. (2008, August 22). Smokestack heat: Fuel of the future? Retrieved April 24, 2010, from cnet news: http://news.cnet.com/8301-11128_3-10019347-54.html
8. System converts smokestack heat to electricity. (2004, May). Retrieved April 24, 2010, from NewScientist: http://www.newscientist.com/article/dn5039-system-converts-smokestack-heat-to-electricity.html
9. Liu, H., & Jiang, J. (2006). Flywheel energy storage- An upswing technology for energy sustainability. Energy and Buildings , 599-604.
10. LaMonica, M. (2008, June 17). One megawatt of grid storage, 10 big flywheels. Retrieved April 24, 2010, from cnet news: http://news.cnet.com/8301-11128_3-9968539-54.html
11. Technology. (n.d.). Retrieved April 24, 2010, from Pentadyne: http://www.pentadyne.com/site/flywheel-ups/technology.html